2.8 Salad Greens and Dressing


  • To identify a variety of salad greens by appearance and flavor.
  • To discuss the principles of emulsion formation.
  • To identify various emulsifying agents and determine their effect on viscosity and permanency of the emulsion.

Laboratory Problems

  • Observe the characteristics of various salad greens.
  • Prepare a salad dressing as an example of an emulsion.
  • Calculate percent oil for each recipe.


  • Emulsion: Colloidal dispersion of one liquid in another, in which liquids are immiscible with each other
    • Temporary – large droplets of oil, separates out quickly, ex. True French Dressing
    • Semi-Permanent – medium-size droplets of oil with a thickening agent, ex. Modified French Dressing and Fruit Salad Dressing
    • Permanent – small-size droplets of oil with a strong emulsifier, ex. Mayonnaise and Cooked Salad Dressing
  • Oil in Water Emulsion: oil droplets are suspended in the water phase, ex. salad dressing, milk
  • Emulsifier: Ingredient with a polar and non-polar end that allows oil and water to mix
    • Give examples from the lab: egg yolk (lecithin), whole egg, paprika, dry mustard
  • Lecithin: Emulsifier present in egg yolk
  • Thickening Agents: Gums, Starch, & Gelatins

Observe various salad greens

Salad Greens Appearance Texture Flavor
Iceberg Lettuce
Leaf Lettuce
Boston Lettuce/Bibb
Swiss Chard


Prepare salad dressing according to the recipes below.

True French Dressing (temporary emulsion)

¼ tsp. dry mustard ¼ tsp. salt
¼ tsp. paprika dash black pepper
¼ tsp. sugar ¼ cup vegetable oil
2 tbsp. apple cider vinegar

Place all ingredients in jar and shake well just before serving.

Modified French Dressing (semipermanent emulsion)

½ tsp. gelatin 1½ tsp. sugar
2 tsp. cold water ½ tsp. salt
1 tbsp. boiling water dash cayenne pepper
½ tsp. dry mustard ½ cup vegetable oil (chilled)
½ tsp. paprika 2 tbsp. vinegar or lemon juice

Hydrate gelatin in cold water and dissolve in boiling water (if necessary, heat over boiling water).  Cool to lukewarm.  Mix dry ingredients and add to oil.  Add vinegar.  Beat 5 minutes with an electric mixer.  Add gelatin and beat 5 more minutes.  Chill about 10 minutes and beat again.

Fruit Salad Dressing (semipermanent emulsion)

⅓ cup sugar 2 tsp. lemon juice
2 tsp. paprika ⅔ cup vegetable oil
1 tbsp. flour 2 tsp. finely grated onion
2 tsp. dry mustard 2 tsp. celery seed
⅓ cup vinegar

Combine dry ingredients in a saucepan.  Add vinegar.  Cook until thick.  Add lemon juice; cool to room temperature.  Add oil in slow stream, beating with electric mixer.  Add grated onion and celery seed.  Stir before serving.

Mayonnaise Dressing (permanent emulsion)

¼ tsp. sugar 1  tbsp. pasteurized whole egg
¼ tsp. salt 1½ tsp. lemon juice
½ tsp. dry mustard ½ cup vegetable oil

In small mixing bowl, combine dry ingredients, egg yolk, and vinegar; beat until well mixed.  Add ½ tsp. oil and beat vigorously with an electric mixer.  Continue adding oil, doubling the amount at each addition, and beating vigorously after each addition.  If mayonnaise is too thick, it may be thinned by adding more lemon juice or vinegar.  If mayonnaise separates, use 2 tsp. of cold water, egg yolk or mayonnaise, and add separated dressing as if it were oil in the above directions.

Cooked Salad Dressing (permanent emulsion)

1 tbsp. + 1 tsp. cornstarch ¼  cup + 2 tbsp. water
2 tbsp. sugar 1 tbsp. vinegar
½ tsp. salt ¼ cup pasteurized whole egg
½ tsp. dry mustard ½ cup vegetable oil

In a saucepan, mix dry ingredients; gradually add water and vinegar.  Heat.  Boil for one minute.  Pour into blender and cool to approximately 55oC so that egg protein will not coagulate.  Add egg and blend until smooth.  Add oil gradually while blender is running.  Continue blending until mixture is thick.



Name of Emulsion Type of Emulsion Emulsifying Agents Size of Fat Globules % Oil Viscosity Stability Flavor
True French Dressing
Modified French Dressing
Fruit Salad
Cooked Salad Dressing


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